This invention relates to an electronic watch which is both thin and water resistant. An electronic watch customarily includes an electronically controlled module for digitally displaying a time signal to indicate the time of day. It also includes a plunger which functions as a switch which in one position closes a circuit in which the time is displayed in hours and minutes. The outer end of the plunger is exposed so it may be actuated by the wearer of the watch to close or open the circuit.
There has been a long-felt, recognized need to provide an electronic watch which is both thin and water resistant.
One prior art suggestion to provide a water resistant water is disclosed in U.S. Pat. No. 2,830,434 dated Apr. 15, 1958 to Trautz. The Trautz watch is not an electronic watch, instead it is of the stem wind type. It includes a watch movement holder 12 which is detachably secured to the frame 48 by a ridge 34 which snaps into a slot 62 in the frame. The stem of the watch movement (not shown) passes outwardly through the tube 30 of the movement holder.
The watch case also includes a shell 46 which telescopically receives the frame 48. The frame is provided with a flange 60 and the shell is provided with a flange 74 which has a downwardly extending skirt 80. The frame and shell are secured together by solder 85 which is placed between the lower end of the skirt and the upper surface of the flange 60. The crystal is made of a transparent synthetic resin and it consists of a thick upper member 36, the lower surface of which is spaced a substantial distance above the watch movement holder. The crystal also includes a first flange 38 which extends downwardly from the upper member and a second flange 42 which extends laterally outwardly from the bottom of the first flange. Both the first and second flanges are located above the watch movement and such positioning of these flanges together with the upward spacing of the upper member 36 relative to the watch movement results in a very thick watch as shown in FIG. 6.
The O-ring 18 is compressed between the upper edge of the watch movement holder, the end of the second flange 42 and the frame 48 in an attempt to provide a water-resistant watch case but no water-resistant sealing means is disclosed for the stem of the watch.
The Trautz watch case would be expensive to manufacture and assemble.
U.S. Pat. No. 3,838,568 dated Oct. 1, 1974 to Zurcher discloses an electronic watch in which the sealing ring 34 is positioned between a flange of the back 32 and the bezel 12 and is held against the bezel by the exteriorly threaded locking ring 26. The substrate 56 is urged against the sealing ring 54 by the springs 112 and 114 thereby urging the sealing ring 34 against the periphery of the dial plate 48. The crystal 16 is seated in the bezel 14 and it does not include any downwardly extending or laterally extending flanges.
The push button 146 has a shank 144 which extends through a bore in the bezel and it is normally urged outwardly by a coil spring. When it is depressed, its end 150 contacts a leg 148 of the spring 132 thereby causing electric changes in the electronic circuit and a digital display of a time or other signal.
No water-resistant seal is disclosed between the contact end of the push button and the substrate.
Zurcher lacks a contact means having a longitudinal portion sealed into a flange of his crystal.
The Zurcher watch is very thick and it is not water resistant.
The two above-mentioned patents are the closest prior art of which I am aware.